E.M. Van Cann

Cone-beam CT in the assessment of mandibular invasion by oral squamous cell carcinoma: results of the preliminary study

This preliminary retrospective study evaluates the diagnostic value of cone-beam computed tomography (CBCT), as a potential standard preoperative procedure, in assessing mandibular invasion by oral squamous cell carcinoma (OSCC) compared with conventional preoperative panoramic radiography (PR), magnetic resonance imaging (MRI) and histological examination of the resection specimen (the golden standard). Between September 2006 and September 2009, 23 patients with histology proven primary OSCC, adjacent to or fixed to the mandible were included. The tumours were classified into four groups, ranging from no bone invasion to evident bone invasion. Sensitivity and specificity for PR were 55% (95% CI [0.350;0.619]) and 92% (95% CI 0.737;0.984]), respectively, both were significantly lower than the 91% (95% CI [0.740;0.909]) and 100% (95% CI [0.845;1]), respectively, for CBCT. MRI showed 82% sensitivity (95% CI [0.608;0.941]) and 67% specificity (95% CI [0.474;0.779]). CBCT has the potential to become a new diagnostic tool in the OSCC screening procedure to predict mandibular invasion or erosion, but its value may be limited by its relatively low sensitivity. A prospective study will start on 64 patients (alpha=0.05; power 0.8; effect size 0.5) to improve these results statistically.

A prospective study on prognostic factors for free-flap reconstructions of head and neck defects

The purpose of this study is to examine a cohort of patients with free-flap reconstruction prospectively and to identify the prognostic factors for postoperative medical and surgical complications. All 150 patients required a free-flap reconstruction after ablative surgery for a defect in the head and neck area. Medical complications and major surgical complications were correlated with patient factors. An ASA score of 3 and male gender were statistically significant prognostic factors for medical complications. The ASA scoring system is a slightly better prognostic factor for medical complications than Charlson comorbidity stage on forward logistic regression analysis. Female gender and an operation time exceeding 10h were statistically significant prognostic factors for major surgical complications.

Donor site complications in bone grafting: comparison of iliac crest, calvarial, and mandibular ramus bone

PURPOSE To compare the donor site complication rate and length of hospital stay following the harvest of bone from the iliac crest, calvarium, or mandibular ramus. MATERIALS AND METHODS Ninety-nine consecutively treated patients were included in this retrospective observational single-center study. RESULTS Iliac crest bone was harvested in 55 patients, calvarial bone in 26 patients, and mandibular ramus bone in 18 patients. Harvesting of mandibular ramus bone was associated with the lowest percentages of major complications (5.6%), minor complications (22.2%), and total complications (27.8%). Harvesting of iliac crest bone was related to the highest percentages of minor complications (56.4%) and total complications (63.6%), whereas harvesting of calvarial bone induced the highest percentage of major complications (19.2%). The length of the hospital stay was significantly influenced by the choice of donor site (P = .003) and age (P = .009); young patients with the mandibular ramus as the donor site had the shortest hospital stay. CONCLUSIONS Harvesting of mandibular ramus bone was associated with the lowest percentage of complications and the shortest hospital stay. When the amount of bone to be obtained is deemed sufficient, mandibular ramus bone should be the first choice for the reconstruction of maxillofacial defects.

The prediction of mandibular invasion by squamous cell carcinomas with the expression of osteoclast-related cytokines in biopsy specimens.

Destruction of bone by tumour is caused by osteoclasts rather than by tumour cells directly. Tumour cells of invasive oral squamous cell carcinomas (SCC) release osteoclast-related cytokines and cytokines activate osteoclasts. The purpose of this study was to investigate the possibility of predicting mandibular invasion by SCC by analysis of the expression of osteoclast-related cytokines in biopsy specimens of SCC, adjacent or fixed to the mandible. Thirty-five biopsy specimens from the pathology archives were examined from patients who had been treated for SCC, adjacent or fixed to the mandible. The patients were divided into those with and without medullary invasion. The expression of tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-11 was studied by immunohistochemical analysis. No significant differences were found in expression of TNF-alpha, IL-6 and IL-11 between biopsy specimens with or without medullary invasion. Quantification of the density of tumour-infiltrating lymphocytes was not reproducible. In conclusion, the expression of TNF-alpha, IL-6 and IL-11 in biopsy specimens of SCC, adjacent or fixed to the mandible, is not an appropriate method for predicting the presence of medullary invasion of the mandible.

Watchful waiting of the neck in early stage oral cancer is unfavourable for patients with occult nodal disease

For cT1/2N0 oral squamous cell carcinoma (OSCC), treatment of the neck is a matter of debate. Two treatment strategies were evaluated in this study: selective neck dissection (SND) and watchful waiting (WW). One hundred and twenty-three SND patients and 70 WW patients with cT1/T2N0M0 OSCC of the tongue, floor of mouth, or buccal mucosa were analysed retrospectively. Extracapsular spread (ECS), 3-year overall survival (OS), and disease-specific survival (DSS) were determined. Twenty-nine percent of SND patients and 13% of WW patients had occult nodal disease. WW-N+ patients showed thicker tumours as compared to WW-N0 patients (5mm vs. 2mm, P=0.02). WW-N+ patients showed significantly more ECS as compared to SND-N+ patients (56% vs. 14%, P=0.016) and had a significantly worse 3-year DSS than SND-N+ patients (56% vs. 82%, P=0.02). For T1 OSCCs, a watchful waiting policy is acceptable if tumour thickness proves to be <4mm. Otherwise, an additional treatment of the neck is advised, since WW-N+ patients show more ECS, with a worse DSS than SND-N+ patients.

Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction

The aim of this study was to investigate the vascular anatomy of the distal forearm in order to optimize the choice between the radial forearm free flap and the ulnar forearm free flap and to select the best site to harvest the flap. The radial and ulnar arteries of seven fresh cadavers were injected with epoxy resin (Araldite) and the perforating arteries were dissected. The number of clinically relevant perforators from the radial and ulnar arteries was not significantly different in the distal forearm. Most perforators were located in the proximal half of the distal one third, making this part probably the safest location for flap harvest. Close to the wrist, i.e. most distally, there were more perforators on the ulnar side than on the radial side. The ulnar artery stained 77% of the skin surface area of the forearm, showing the ulnar forearm free flap to be more suitable than the radial forearm free flap for the restoration of large defects.

Bone spect reduces the number of unnecessary mandibular resections in patients with squamous cell carcinoma

Los carcinomas epidermoides de la cavidad oral (CECO) tienen tendencia a extenderse a la mandíbula debida a su estrecha relación anatómica. En la actualidad, si existe una afectación de la medular de la mandíbula los cirujanos preconizan una resección segmentaria de la mandíbula, lo que suele conllevar numerosos inconvenientes funcionales y estéticos, además de una alta morbilidad para el paciente. Si la invasión no llega a la medular se suele realizar una osteotomía marginal de la zona mandibular afecta. Se han descrito altos porcentajes (35-70%) de resecciones mandibulares, segmentarias y marginales sin confirmación histológica de invasión ósea. En la actualidad en el protocolo rutinario de pruebas en un paciente con un CECO se incluye la exploración de la cavidad oral, radiografías (ortopantomografia) y tomografía axial computerizada y/o resonancia magnética. Con una simple inspección clínica de la boca del paciente es imposible de valorar el grado de extensión ósea por el tumor. Las radiografías convencionales detectan la afectación mandibular cuando se produce una perdida de la masa mineral ósea entre 30-50%. La utilización de la tomografía computerizada o RM, aunque ha mejorado notablemente la detección de la invasión del hueso, puede conllevar falsos positivos por infecciones dentales, proceso inflamatorios, edema o esclerosis por reacción del tumor primario, etc. Muchos autores consideran la gammagrafia ósea (GO) una prueba de gran utilidad en la detección de la invasión ósea, aunque en la actualidad en muchos hospitales no es considerada una prueba rutinaria de diagnóstico de extensión preoperatorio en los CECO. El objetivo del presente estudio es determinar el valor de la GO para la invasión mandibular por el CECO. El estudio se realizo a 79 pacientes (64 hombres y 30 mujeres) con CECO en inmediaciones de la mandíbula, entre 1999-2003. De los 79 pacientes con diagnóstico de un CECO, 39 eran de suelo de boca, 21 de área retromolar, 16 de encía y 3 de mucosa yugal. A todos pacientes tras las pruebas rutinarias de diagnóstico preoperatorio de un CECO, se les realizó una GO de cabeza y cuello. En todos los pacientes se efectuó una resección mandibular (segmentaria/marginal) sin conocer los resultados de la GO. Tras el estudio histológico de las piezas quirúrgicas se confeccionaron 3 grupos: Grupo CM, tenían invasión tumoral de la cortical y medular de la mandíbula, Grupo C, solo invasión cortical y Grupo 0, sin invasión mandibular. Los criterios de exclusión fueron osteoradionecrosis, osteomielitis, tratamiento radioterápico traumatismo mandibular. El estudio histológico de las mandíbulas resecadas mostró invasión de la medular ósea en 43 pacientes (grupo CM), en 7 casos solo hubo invasión de la cortical ósea (grupo C) y en 29 casos no se reveló afectación del hueso mandibular (grupo 0). Se realizo una resección segmentaria de la mandíbula en 30 casos, de los cuales solamente en 2 casos no se confirmó la invasión ósea; en cambio, de los 44 pacientes que se realizó una resección mandibular marginal, en 22 casos no se evidenció afectación ósea histológica. La GO fue positiva en 62 pacientes y negativa en 17 pacientes; en ninguno de los 50 pacientes con invasión ósea mandibular confirmada histológicamente, la GO fue negativa (sensibilidad 100%). Según el estudio la GO reduce las resecciones mandibulares en un 59% del total de los pacientes del estudio. Se ha descrito un alto porcentaje (35-70%) de resecciones mandibulares sin evidencia de invasión ósea, lo que enfatiza la necesidad de un método diagnóstico más eficaz. Especialmente, en los pacientes con CECO que requieran una resección mandibular marginal se pueden beneficiar de una GO. Asimismo, muchas resecciones mandibulares se pueden limitar a los tejidos blandos y el periostio sin resecar hueso que beneficiaria a muchos pacientes de CECO de edad avanzada que tienen atrofia mandibular. En la mayoría de los hospitales de España no se utiliza la GO como método de detección de invasión mandibular por los CECO de forma rutinaria y la TC sigue siendo la prueba de imagen preferida. Creo interesante el presente trabajo para reconsiderar el tipo de resección mandibular en pacientes que presentan dudas en el grado de invasión tumoral mandibular.